Laudation to Prof. Dr. Hans-Toni Ratte--towards conceptual, theory-based ecological science and its transfer to the applied field of ecotoxicology

Dr. Theo C. M. BrockAlterra, Wageningen University and Research CentreP.O. Box 47, 6700 AA, WageningenThe NetherlandsProf. Dr. Hans Toni Ratte: A pioneer in mechanistic effect modelling and an excellent lecturer. More than 20 years ago, Drs. Hans Toni Ratte and Peter Leeuwangh organized a German-Dutch meeting in Ecotoxicology that took place at RWTH Aachen University. As a junior scientist with a PhD degree in Aquatic Ecology, and hardly no international network in the field of environmental risk assessment, I was honoured with the invitation to present my post-doc research on the ecological impact of the insecticide chlorpyrifos in indoor freshwater microcosms. I considered this meeting as a milestone of my beginning career as aquatic ecotoxicologist. At this German-Dutch meeting, representatives of different stakeholder groups (academia, regulators, industry, consultants) were present, many involved with the environmental risk assessment of pesticides. Here, I realized the importance of applied environmental research and its direct use in decision making. Here, I also met for the first time Hans Toni Ratte, a respected colleague with a broad scientific interest covering topics like applied ecology [1-3], ecotoxicology [4-7], ecotoxicological statistics [8,9], mechanistic effect models [10], and guidance development [11].Within the scientific community it is more and more recognized that the extrapolation of results from laboratory toxicity experiments to complex field communities requires the analysis of the interactions between different trophic levels in ecosystems, which can be done by means of model ecosystems and mechanistic modelling. Within this context it is worthwhile mentioning that already in the early 1990s of the past century Hans Toni Ratte started with the supervision of a research project at RWTH Aachen University to integrate and extrapolate ecotoxicological experiments by means of model ecosystem research and computer simulation models [10,12,13]